Notary Project

The Notary Project is a CNCF incubating set of specifications and tools for signing and verifying container images and other OCI artifacts. It provides Notation, a CLI and library for signing artifacts stored in OCI-compliant registries. The project defines standards for signature formats, trust policies, and verification workflows to secure software supply chains.

Notary Project is listed with 4 APIs on the APIs.io network. Tagged areas include Cloud-Native, Container Security, Image Signing, Incubating, and OCI.

The Notary Project catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Notary Project’s developer surface includes documentation, getting-started guide, engineering blog, FAQ, changelog, and 17 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

32.8/100 thin ▬ flat Agent 1/100 human only Front door AI 1/6 silent Heartbeat 40/100 alive self hosted · Apache-2.0 Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemium

4 APIs

Cloud-Native Container SecurityImage SigningIncubating OCI Verification

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 32.8/100 · thin

Contract Quality 5.0 / 19

Developer Ergonomics 4.7 / 15

Access Clarity 1.2 / 15

Operational Transparency 2.6 / 10

Contract Governance 0.9 / 9

Discoverability 5.2 / 8

Regulatory Posture 1.6 / 15

Open Source Surface 10.0 / 10

Agent readiness — 1/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 75 points between them, because both conditional facets apply and carry 25 points together. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Show this score on your site.

It updates itself when the score changes. Paste this where you link to your API docs:

<a href="https://apis.io/providers/notary/"><img src="https://apis.io/badge/notary/card.svg" alt="Notary Project on APIs.io — Kin Score by API Evangelist"></a>

Other styles, a README pill and a shields.io endpoint are on the badge page.

Raise your score.

Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes

12 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Access Clarity scores 7.9 — up to +18.4 composite points
Contract Quality scores 26.7 — up to +18.3 composite points
Developer Ergonomics scores 31.0 — up to +13.8 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/notary/apis.yml: open an issue on github.com/api-evangelist/notary to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 4

Individual APIs this provider publishes, each with its own machine-readable definition.

Notary Project Signing Specification

The Notary Project specification defines the signature envelope format, trust store and trust policy for container image signing and verification. It supports multiple signature...

Notation CLI

Notation is the command-line tool that implements the Notary Project specifications for signing and verifying OCI artifacts stored in container registries. It supports signing w...

notation-go Library

notation-go is the official Go library for signing and verifying OCI artifacts using the Notary Project specifications. It provides the programmatic interface used by the Notati...

Notation Plugin Extensibility

The Notation plugin extensibility specification defines the interface that third-party plugins must implement to integrate with Notation for key management, signing, and verific...

Notary Project API pricing

Not yet checked against Notary Project's own pricing page. Compiled by API Evangelist on 2026-05-04; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free freemium	Free
Professional paid	Free
Enterprise enterprise	—

Plan details, limits and sources →

Rate limits

Free Tier Default: 10 requests per minute
Free Tier Monthly Quota: 1000 requests per month
Professional Tier Default: 100 requests per minute

Compiled by API Evangelist, not yet checked against Notary Project's documentation. All 5 limits →

Pricing Plans 1

Published pricing tiers and plan structures.

Notary Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Notary Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Notary Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Notary Context

7 classes · 32 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Notary Project — jsonschema rules

6 rules · 4 warnings 2 info

SPECTRAL

JSON Schema 4

Standalone JSON Schema definitions for this provider's data models.

Notary Project Plugin Protocol

0 properties

JSON SCHEMA

Notation Plugin Protocol

0 properties

JSON SCHEMA

Notary Project JWS Signature Envelope

4 properties

JSON SCHEMA

Notary Project Trust Policy

2 properties

JSON SCHEMA

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Notary Domain Security

TLSv1.3 · HSTS

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 6

Reference material describing how the API behaves

ContributionGuide

Documentation

JSONSchema

JSONSchema

JSONSchema

JSONSchema

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

JSONLD

JSONLD

Build 3

SDKs, sample code, and the tooling you integrate with

CodeOfConduct

CodeOfConduct

GitHubOrganization

GitHubOrganization

GitHubRepository

GitHubRepository

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 5

Status, limits, changes, and where to get help

RateLimits

IssueTracker

Releases

FAQ

ChangeLog

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

License

License

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: notary
name: Notary Project
description: The Notary Project is a CNCF incubating set of specifications and tools for signing and verifying container images
  and other OCI artifacts. It provides Notation, a CLI and library for signing artifacts stored in OCI-compliant registries.
  The project defines standards for signature formats, trust policies, and verification workflows to secure software supply
  chains.
url: https://notaryproject.dev
deliveryModel:
  model: self-hosted
  license: Apache-2.0
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: low
  source:
  - plans
  - security
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/notary.png
tags:
- Cloud-Native
- Container Security
- Image Signing
- Incubating
- OCI
- Verification
tags_raw:
- Cloud Native
- Container Security
- Image Signing
- Incubating
- OCI
- Verification
created: '2026-03-16'
modified: '2026-04-28'
specificationVersion: '0.23'
type: Index
apis:
- aid: notary:notary-spec
  name: Notary Project Signing Specification
  description: The Notary Project specification defines the signature envelope format, trust store and trust policy for container
    image signing and verification. It supports multiple signature formats and integrates with OCI distribution registries
    for storing signatures alongside container images. The specification enables end-to-end supply chain security from build
    to deployment.
  humanURL: https://notaryproject.dev/docs/
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://notaryproject.dev/docs/
  - type: Reference
    url: https://github.com/notaryproject/specifications/blob/main/specs/trust-store-trust-policy.md
  - type: GitHubRepository
    url: https://github.com/notaryproject/specifications
  - type: JSONSchema
    url: json-schema/notary-trust-policy-schema.json
  - type: JSONSchema
    url: json-schema/notary-signature-envelope-schema.json
  tags:
  - Signing
  - Specification
  - Verification
- aid: notary:notation-cli
  name: Notation CLI
  description: Notation is the command-line tool that implements the Notary Project specifications for signing and verifying
    OCI artifacts stored in container registries. It supports signing with certificates stored in trust stores, configuring
    trust policies for verification, and extends to third-party key management systems via a plugin model.
  humanURL: https://notaryproject.dev/docs/user-guides/installation/cli/
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://notaryproject.dev/docs/user-guides/installation/cli/
  - type: GettingStarted
    url: https://notaryproject.dev/docs/user-guides/installation/
  - type: Reference
    url: https://github.com/notaryproject/notation/blob/main/specs/notation-cli.md
  - type: GitHubRepository
    url: https://github.com/notaryproject/notation
  - type: ChangeLog
    url: https://github.com/notaryproject/notation/releases
  tags:
  - CLI
  - OCI
  - Signing
  - Verification
- aid: notary:notation-go
  name: notation-go Library
  description: notation-go is the official Go library for signing and verifying OCI artifacts using the Notary Project specifications.
    It provides the programmatic interface used by the Notation CLI and enables Go applications to integrate artifact signing
    and verification into their own workflows without invoking the CLI directly.
  humanURL: https://github.com/notaryproject/notation-go
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://pkg.go.dev/github.com/notaryproject/notation-go
  - type: GitHubRepository
    url: https://github.com/notaryproject/notation-go
  tags:
  - Client Library
  - Go
  - SDK
  - Signing
- aid: notary:notation-plugin-framework
  name: Notation Plugin Extensibility
  description: The Notation plugin extensibility specification defines the interface that third-party plugins must implement
    to integrate with Notation for key management, signing, and verification operations. Plugins allow Notation to work with
    hardware security modules, cloud key management services, and other external credential systems.
  humanURL: https://github.com/notaryproject/specifications/blob/main/specs/plugin-extensibility.md
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - type: Documentation
    url: https://github.com/notaryproject/specifications/blob/main/specs/plugin-extensibility.md
  - type: Reference
    url: https://pkg.go.dev/github.com/notaryproject/notation-plugin-framework-go/plugin
  - type: GitHubRepository
    url: https://github.com/notaryproject/notation-go
  - type: JSONSchema
    url: json-schema/notary-plugin-schema.json
  - type: JSONSchema
    url: json-schema/notary-plugin-protocol-schema.json
  tags:
  - Extensibility
  - Key Management
  - Plugins
  - Signing
  tags_raw:
  - Extensibility
  - Key Management
  - Plugin
  - Signing
common:
- type: Plans
  url: plans/notary-plans-pricing.yml
- type: RateLimits
  url: rate-limits/notary-rate-limits.yml
- type: FinOps
  url: finops/notary-finops.yml
- type: IssueTracker
  url: https://github.com/notaryproject/specifications/issues
- type: Releases
  url: https://github.com/notaryproject/specifications/releases
- type: CodeOfConduct
  url: https://github.com/notaryproject/.github/blob/main/CODE_OF_CONDUCT.md
- type: ContributionGuide
  url: https://github.com/notaryproject/.github/blob/main/CONTRIBUTING.md
- type: License
  name: Apache-2.0
  url: https://github.com/notaryproject/specifications/blob/main/LICENSE
- type: DomainSecurity
  url: security/notary-domain-security.yml
- type: Website
  url: https://notaryproject.dev
- type: Documentation
  url: https://notaryproject.dev/docs/
- type: GettingStarted
  url: https://notaryproject.dev/docs/user-guides/installation/
- type: Blog
  url: https://notaryproject.dev/blog/
- type: FAQ
  url: https://notaryproject.dev/docs/faq/
- type: GitHubOrganization
  url: https://github.com/notaryproject
- type: GitHubRepository
  url: https://github.com/notaryproject/notation
- type: ChangeLog
  url: https://github.com/notaryproject/notation/releases
- type: JSONSchema
  url: json-schema/notary-trust-policy-schema.json
- type: JSONSchema
  url: json-schema/notary-plugin-schema.json
- type: JSONSchema
  url: json-schema/notary-plugin-protocol-schema.json
- type: JSONSchema
  url: json-schema/notary-signature-envelope-schema.json
- type: JSONLD
  url: json-ld/notary-context.jsonld
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Notary Project API — frequently asked questions

Does Notary Project have an API?

Yes. APIs.io lists 4 APIs from Notary Project, including Notary Project Signing Specification, Notation CLI and notation-go Library, and 1 more.

How much does the Notary Project API cost?

APIs.io lists 3 pricing plans for Notary Project, with each plan's price, limits and inclusions under Pricing on this page.

Is the Notary Project API ready for AI agents?

Notary Project has a Kin Score of 32.8 out of 100 (thin) and an Agent Readiness score of 0.6 (human-only), scored by API Evangelist on 2026-11-06.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/notary"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/notary/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/notary/evidence"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.